Курсор для гетт такси рабочее время

/****** Script for SelectTopNRows command from SSMS  ******/
DECLARE @dt1 DATETIME = '20190703 00:00'
DECLARE @dt2 DATETIME ='20190704 23:59'
DECLARE @tm1 DATETIME = '19000101 00:00'
DECLARE @tm2 DATETIME = '19000101 23:59'

DECLARE @C_UserStates CURSOR

DECLARE @TestTable TABLE (UserId uniqueidentifier, [State] int, TimeChange datetime, ICode int);

DECLARE @FilteredTable TABLE (UserId uniqueidentifier, [State] int, TimeChange datetime, ICode int);

INSERT INTO @FilteredTable
SELECT UserId, [State], TimeChange, ICode
  FROM [oktell].[dbo].[A_UserStateHistory]
where TimeChange between @dt1 and @dt2 and UserId = '9EE34782-68B6-4C6C-819F-CD352D670BCF'
ORDER BY TimeChange

SET @C_UserStates  = CURSOR SCROLL
FOR
SELECT * FROM @FilteredTable

DECLARE @Count int
SET @Count =
(SELECT COUNT(*)
    FROM @FilteredTable)

DECLARE @Iterator int
SET @Iterator = 0

DECLARE @UserId uniqueidentifier
DECLARE @State int
DECLARE @TimeChange datetime
DECLARE @ICode int

DECLARE @TempCode int
SET @TempCode = -1


OPEN @C_UserStates

WHILE @Iterator != @Count
    BEGIN
        FETCH @C_UserStates INTO @UserId,@State,@TimeChange,@ICode;
        IF @ICode = 0
            INSERT @TestTable VALUES(@UserId,@State,@TimeChange,@ICode)
        ELSE
            BEGIN
                IF @TempCode = 0
                INSERT @TestTable VALUES(@UserId,@State,@TimeChange,@ICode)
            END

        SET @TempCode = @ICode
        SET @Iterator = @Iterator + 1
    END

CLOSE @C_UserStates

DECLARE @FinalTable TABLE(UserId uniqueidentifier, [State] int, LenTime float, ICode int)

DECLARE @C_Half CURSOR

SET @C_Half  = CURSOR SCROLL
    FOR
    SELECT * FROM @TestTable

SET @Count = (SELECT COUNT(*) FROM @TestTable)
SET @Iterator = 0
OPEN @C_Half

DECLARE @startTime datetime
DECLARE @endTime datetime
SET @TempCode = -1

WHILE @Iterator != @Count
    BEGIN
        FETCH @C_Half INTO @UserId,@State,@TimeChange,@ICode;
        IF @startTime IS NOT NULL AND @TempCode = 0
            BEGIN
                SET @endTime = @TimeChange
                INSERT @FinalTable VALUES(@UserId, @State, datediff(SECOND, @startTime, @endTime), @ICode)
            END
        SET @TempCode = @ICode
        SET @startTime = @TimeChange
        SET @Iterator = @Iterator + 1
    END

CLOSE @C_Half
select SUM(LenTime) from @FinalTable